1. Field of the Invention
The present invention relates to a printed wiring board which is formed with a packaging substrate for mounting an IC chip and a transmission substrate mounted on the packaging substrate.
2. Discussion of the Background
Conventionally, frequencies of signals to be transmitted through a packaging substrate were usually set in one range, and such a substrate was designed to achieve impedance matching according to the frequency range. Japanese Laid-Open Patent Publication No. 2006-91753 describes a technology to transmit high-speed signals. The entire contents of this publication are incorporated herein by reference.